The present invention relates to tie members for forming an angled joint between two obliquely cut hollow members. This joint may in particular be employed in the production of panel edgings and the fixed or moving frames of doors or windows, etc.
Joining systems are known which are made up of two clamping members which are inserted in the hollow members to be joined facing one another and are moved apart from one another to apply pressure to the walls of the hollow members and to clamp the latter in such a way that their obliquely cut edges bear against one another in the plane of junction.
One kind of system of this nature is for example described in U.S. Pat. specification no. 3,848,390. In this system, one of the clamping members is a deformable clip which provides the clamping action by means of the give afforded by its resilience and by means of the deformation which its is forced to undergo when moved in relation to the other locking member. The clip has engagement studs which enable it to slide along the hollow members. A drawback of systems of this kind is that they can only be used once, since, in the course of tightening up, the clip suffers permanent deformation which makes it unable to be removed and used again. Furthermore, the mechanical strength of the joints produced with these systems, in which the hollow members are held together by a resilient member, is relatively low.
What is more, the operation of fitting these systems is awkward to carry out. The system is in fact formed by two separate and independent clamping members which have to be inserted simultaneously in the hollow members in the correct respective positions while at the same time lining up the engagement studs of the clip opposite holes contained in the hollow members so that the said studs will engage in them as the two clamping members are moved apart.
Another kind of system, which is described in Belgian patent specification No. 692.401 for example, overcomes the disadvantage arising from the resilient clip by providing two non-deformable clamping parts which, when they are moved apart, apply pressure against the inner faces of the hollow members and clamp them in place without deforming. Screws are screwed into the hollow members to form abutments which enter grooves in that clamping part which is situated on the outside of the angle and prevent it from slipping relative to the hollow members. The mechanical strength of this system is good provided it is fitted with absolute correctness. In the event of the parts being faultily machined or the abutments being faultily positioned in the hollow members, it may be impossible to join the hollow members or it may be possible to form only an imperfect joint with a gap between the hollow members at the plane of junction. Furthermore, fitting this system is an operation which is lengthy and difficult and it calls for tapped holes to be provied in the hollow members at very precise positions, for the two clamping parts, which are separate and independent, to be held in position with respect to one another and to be inserted in the hollow members and to be so positioned that the aforementioned grooves in one of the parts lines up with the tapped holes in the hollow members, for the abutments to be screwed into these holes so that they enter the grooves and for the two parts to be moved apart so as to clamp the assembly.
One object of the invention is a tie member which is of the same general kind as those described above and which comprise two non-deformable parts, but which does not suffer from the drawbacks of such systems.
Another object is in particular to remove the danger of producing a defective joint by ensuring that the sections are suitably tightened against one another without the need for any special precautions to be taken.
A further object is to simplify the operation of fitting the tie member and to enable this to be done quickly.
Yet another object is to simplify the operation of preparing the hollow members by doing away with the need to tap the bores made in the members and by making it unnecessary for these bores to be positioned with extreme accuracy.
A still further object is to enable the tie member to be re-used.